Scientists tracing the real time impact of viruses in the wild have found that entire amphibian communities are being killed by closely related viruses introduced to mountainous areas of northern Spain.

The results have wider significance as emerging diseases like Ebola threaten all animal groups, including humans, where viruses have crossed the species barrier from other animals.

"One of the main threats to biodiversity is the emergence of infectious diseases that can impact dramatically on entire communities. We have identified a striking example of two viruses that are repeatedly overcoming the species barrier with catastrophic consequences," said Stephen Price from University College London's Genetics Institute and author of the research.

The viruses are part of the Ranavirus group referred to as common midwife toad virus (CMTV) which previously was known only to cause declines in Britain's common frog.

But from surveys across 15 locations in Picos de Europa National Park, Spain, between 2005-2012, the team found animals from six amphibian species dead or dying from infection with CMTV.

The Spanish frog called common midwife toad, common toad and alpine newt were the worst affected, showing levels of population collapse which could ultimately prove catastrophic to amphibian communities and their ecosystems.

"Indications are that related viruses are beginning to emerge in other locations in Europe and it's important to understand the origins and movement of these viruses to try to limit further amphibian declines," concluded Stephen Price.